1. Field of the Invention
The present invention relates to filtering and purifying devices for tobacco smoke. More specifically, the present invention relates to a multi-stage tobacco smoke filtering apparatus which filters both second-hand smoke exhaled by a smoker, and side-stream smoke which is evolved from the burning tip of a cigar or cigarette.
2. Description of the Prior Art
Tobacco has been a staple cash crop of the American eastern seaboard since the earliest European settlers set foot in the Americas. Beginning in the middle 1700's, large exportation of tobacco products to Europe made smoking tobacco a very popular personal habit. However, it was not until the 20th century that smoking cigarettes became popular in Western culture. Cigarette smoking in the U.S. increased steadily throughout both World War I and World War II, in spite of the increasing scientific evidence that linked cigarette smoking with two previously rare lung diseases: lung cancer and emphysema.
In the 1950's, with the increasing public perception that cigarette smoking and lung cancer were linked, filtered cigarettes were first mass-marketed in the U.S. They quickly began outselling unfiltered cigarettes. Tests had shown that some, but not all, of the integral filters placed in cigarettes lowered the amount of "tar," (heavy hydrocarbon substances), and nicotine which were inhaled by the consumer. Both "tar" and nicotine had been shown to be carcinogenic and mutagenic under certain laboratory conditions.
Then, on Jan. 11, 1964, U.S. Surgeon General Luther Terry issued the now-famous report linking smoking with lung cancer. Actually, the report was a review and summary of evidence that had been accumulated by scientists since the beginning of the 1950's. This date, however, marks the official origin of the now widely held belief that cigarette smoking is both an individual and public health hazard.
It is generally accepted that smoking is a primary causative factor of lung cancer and emphysema. Moreover, many recent studies appear to indicate that inhalation of a smoker's second-hand or side-stream smoke also raises the risk of contracting a smoking-related disease. These more recent studies have been the impetus for government restrictions on smoking based on its deleterious effect on the public health. For instance, early on, cigarette advertising was banned from television. More recently, federal and state legislation has been enacted which bans smoking from most work places, restaurants, airplanes, and other public areas. Despite the many restrictions on smoking in public, many Americans continue to smoke cigarettes regularly. This endangers the health not only of the smokers, but those around them who are subjected to the second-hand and side-stream smoke produces by the smokers. To lower the danger of smoking, as well as to protect non-smokers from tobacco smoke, numerous cigarette filtering media and devices have been patented.
Of particular note are the following patents: U.S. Pat. No. 4,369,798, issued Jan. 25, 1983, to A. C. Jackson, which describes a combination cigarette holder and cigarette smoke catcher. This device includes a cigarette-holding body having a pair of cylindrical passageways passing therethrough. One passage holds the unlit end of a cigarette, and includes a one-way valve to permit smoke to pass through the passageway when the user inhales on a mouthpiece. The second passageway terminates in a smoke catcher cartridge. This passageway also includes a one-way valve which allows smoke exhaled by the user to enter the smoke catcher cartridge. The combination of valves precludes smoke exhaled by a user (second-hand smoke) from being released into the atmosphere. This device, however, does not trap side-stream smoke, i.e., smoke which is evolved from the burning tip of the cigarette.
A very similar device is described in U.S. Pat. No. 4,790,332, issued Dec. 13, 1988, to F. E. Wallace. Here the device is essentially identical to the Jackson device, above, but also includes a filter housing which fits over the burning tip of the cigarette. Smoke is inhaled from the housing through a first passageway, and exhaled back into the housing through a second passageway back. The walls of the housing are formed from air-permeable bilayer filter media. Once the pressure inside the housing is sufficiently greater than the pressure outside the housing, smoke from within the housing will be forced through the filter media to the ambient environment.
Another related smoke catching device is described in U.S. Pat. No. 4,899,766, issued Feb. 13, 1990, to J. R. Ross, Jr. This device includes a housing designed to accommodate a pipe, cigar, or cigarette, with the lip portion of the smoking product extending outside of the housing. The housing may also include a port for mounting a lighter in the proper orientation to ignite the smoking product. After being light, smoke is inhaled by the user, and exhaled into a second chamber which acts a smoke dump. The smoke dump may include filtering means, and/or a fan to vent smoke to an external environment.
A cigarette-smoke filtering device is described in U.S. Pat. No. 4,993,435, issued Feb. 19, 1991, to S. McCann. The McCann device is very similar to the Wallace device described above. Here, a housing defines two parallel chambers, each having an air inlet and an air outlet. The first chamber is shaped to encase the entire length of a cigarette, with the filter end of the cigarette extending outside of the chamber. The second chamber includes a plurality of filtering elements which filter cigarette smoke which is exhaled by the user into the chamber. Smoke inhaled by the user from the cigarette contained in the first chamber is exhaled into the second chamber, where the smoke is filtered prior to being vented back into the ambient environment.
U.S. Pat. No. 5,078,155, issued Jan. 7, 1992, to R. L. Grandel, describes an ashtray which includes a cylindrical housing mounted on a pair of semi-circular mounting elements. The mounting elements may be adjusted so that ashes from a cigarette placed into the ashtray fall into the cylindrical housing.
U.S. Pat. No. 5,088,508, issued Feb. 18, 1992, to S. A. Duncan, describes a "smokeless" ashtray for capturing side-stream tobacco smoke. The ashtray has a smoke capture chamber which includes an ignition source which burns the side-stream smoke which is evolved from the cigarette. This device does not include means to capture smoke exhaled by a smoker.
U.S. Pat. No. 5,160,518, issued Nov. 3, 1992, to J. G. Vega, Jr., describes a smoke filtering apparatus which also includes two parallel chambers: a first chamber to hold a cigarette or other smoking product, and a second chamber into which the user exhales tobacco smoke which is then filtered prior to being released into the ambient environment.
U.S. Pat. No. 5,240,014, issued Aug. 13, 1993, to S. C. Deevi et al., discloses a method to catalytically convert carbon monoxide into benign substances using a carbonaceous heat source which includes a catalytic precursor. When the carbonaceous heat source is ignited, the catalytic precursor within the heat source is converted into a catalyst, which then catalyzes the conversion of carbon monoxide into non-toxic substances.
A French Patent, No. 687,571, issued Aug. 11, 1930, describes a cigarette holding device which includes a bell-shaped housing into which a cigarette is placed. The bell housing includes perforations passing therethrough, and a mouthpiece which grasps the end of a cigarette.
None of the above references, taken alone, or in any combination, is seen as describing the present invention.